JP2007518025A - How to start the engine - Google Patents

Abstract

  System, apparatus, and method for starting an engine. The system, apparatus, and method include determining a first fuel amount based on engine temperature, providing a first fuel amount to the engine during an initial cycle of the engine, and engine temperature. And determining a second fuel amount based on, then providing the second fuel amount to the engine and transitioning to an alternative fuel supply strategy.

Description

  The disclosed invention relates generally to starting an engine, and more particularly to a system, apparatus, and method for improving engine starting.

  An internal combustion engine generally corresponds to the current engine operating level or load, often the throttle position, and sometimes to a desired engine operating level or an idle air control valve (IACV) or throttle bypass circuit. It is manipulated and controlled based on consideration of the load, the amount of fuel and air injected into the engine cylinder, the ignition timing if appropriate, and other parameters as appropriate. The engine generally operates differently after starting and during starting.

  In addition, the engine is typically started in one of two ways: automatic or manual. Automatic startup may use a power source such as a battery. The battery can be used to power the electric motor until the engine begins to circulate from the combustion that occurs in the cylinder to rotate the engine while fuel and air are being supplied to the cylinder. When manual start is used, the engine can be rotated manually, such as by kickstart on a motorcycle.

  In general, during startup, the cylinders of the engine are supplied with more fuel and air than when the engine is idle under normal operating conditions. The additional fuel and air may be needed, for example, to wet the fuel supply surface, make up for the lack of fuel vaporization, and create a combustible fill in the cylinder. However, excessive fuel supply generally reduces engine efficiency and increases the emission of undesirable emissions from the engine.

  Further, inadequate amounts of fuel and air, or improper timing of fuel and air supply to the engine can prevent the engine from starting.

  Accordingly, there is a need for a system, apparatus, and method that provides an appropriate amount of fuel and air to the engine and supplies the fuel and air at the appropriate time to optimize engine startup.

  Also, a system that supplies the appropriate amount of fuel and air to the engine at start-up, and supplies that fuel and air at the appropriate time to maximize efficiency and minimize the emission of unwanted emissions from the engine, Devices and methods are also needed.

  In addition, systems, devices, and methods for transitioning from optimal engine starting conditions to optimal engine operating conditions, while encouraging preferred engine operation, and engine efficiency, and optimal while encouraging reduced undesired composite emissions What is needed is a system, apparatus, and method for transitioning from a clean start state to an optimal operating state.

  Accordingly, the engine starting systems, devices, and methods described herein provide a solution to the shortcomings of previous engine starting systems, devices, and methods. Those skilled in the art will readily appreciate that other details, features, and advantages of starting the engine will become more apparent in the following detailed description of the preferred embodiment.

  In one embodiment, starting the engine determines a first fuel amount based on the engine temperature, provides the first fuel amount to the engine during the first cycle of the engine, and determines the first fuel amount based on the engine temperature. A system, apparatus, and method are provided for determining a fuel quantity of two and then providing a second fuel quantity to the engine and transitioning to an alternative fuel delivery strategy.

  In another embodiment, starting the engine retrieves a first fuel amount from a starting fuel table based on the engine temperature and the first fuel amount to the engine during the first cycle of the engine. Provide a system, apparatus, and method for providing and retrieving a second fuel quantity from a startup fuel table based on engine temperature and then providing the engine with a second fuel quantity and transitioning to an alternative fuel delivery strategy To do.

  In yet another embodiment, starting the engine retrieves a first fuel amount from a start fuel table based on the engine temperature, provides the first fuel amount to the engine during the first cycle of the engine, and Systems, apparatus, and methods are provided for determining an amount of a second fuel from an amount of one fuel and then providing an amount of a second fuel to an engine and transitioning to an alternative fuel delivery strategy.

  The engine fuel supply includes a processor coupled to a signal corresponding to the engine temperature and coupled to the fuel supply controller. The processor of the device determines a first fuel amount based on the engine temperature, and supplies the first fuel amount to the engine via a fuel supply controller during the first cycle of the engine, to the engine temperature. A second fuel amount is determined based on the first fuel amount, and then the second fuel amount is provided to the engine via the fuel supply control device to transition to an alternative fuel supply strategy. .

  Also provided is a computer readable medium capable of operating as such a device or within such a system or causing a processor to perform such a method.

  The accompanying drawings, in which like reference numerals are used to designate like parts or steps, are included to provide a better understanding of engine starting and are incorporated herein and are FIG. 2 shows an engine start embodiment which constitutes a part and serves to explain the principle of engine start with the description.

Reference will now be made to embodiments of systems, devices, and methods for starting an engine.
Any reference herein to “an embodiment”, “an embodiment”, or a similar reference to an embodiment refers to a particular feature, structure, or structure described in connection with that embodiment. It is intended to indicate that the characteristic is included in at least one embodiment of the invention. The appearance of these terms in various places in the specification is not necessarily all referring to the same embodiment. References to “or” are intended to be more comprehensive, so “or” refers to one or the other of the terms indicated by “or” or a plurality of terms indicated by “or”. obtain.

  For the sake of brevity, the drawings and descriptions contained herein show and describe elements that are particularly relevant to engine startup, excluding some elements found in general engine management systems and engines, for example. Please understand that. This is because the construction and implementation of these other elements are well known to those skilled in the art of engine starting and operation, and their description does not facilitate a better understanding of engine starting. It should also be understood that the engine start embodiments described herein are merely examples of ways to embody engine start and are not exclusive. For example, engines and motorcycles powered by gasoline and other hydrocarbons described herein, such as small engines such as those used in diesel engines, truck engines, lawnmowers and other equipment, for example Those skilled in the art of engine starting and operation will understand that it can be readily applied to starting other engines.

  Designers of engines, engine components, and components associated with engines may aim to make each combustion event repeatable in each cylinder. However, each combustion event tends to be different from the others even when the engine is operating at steady state. That is because, at least in part, each combustion event involves many factors that occur in a short period of time, and even small changes in these factors can change the combustion event. Although not all of these factors are discussed here, a few factors are considered as examples.

  For example, the amount of fuel supplied to the cylinder may be the pressure of the injected fuel, the amount of fuel supplied, the wall of the intake pipe extending from the fuel injector to the cylinder, the surface of the intake valve and the air stream in the intake pipe, etc. It can vary depending on a number of factors, including the deposition of fuel on the collaborative source, collection of fuel therefrom, and the voltage applied to the injector when the fuel injector is operated on a fuel injection engine.

  The engine starting system, apparatus, and method described herein may be applied to at least a carburetor engine and a fuel injected engine, although the following are generally described in the context of a fuel injection engine Note that this is done.

  With respect to an attached fuel source, once the engine is operating, the amount of fuel that is added to and removed from the attached fuel source generally changes, especially when the fuel supply increases or decreases, but after the operation begins, the fuel is usually Some of these additional fuel sources add or remove. However, when the engine is first cold started, there may be no fuel in or on the attached fuel source, so collecting or removing the fuel is directed to the cylinder by these attached sources. In some cases, only from the fuel stream. Furthermore, the amount of fuel removed by such an attached fuel source can be substantial, which is necessary, for example, to wet various surfaces of the filler. It will be appreciated that starting the engine provides a unique situation with respect to the fuel supply and the fuel source attached to the fuel.

The quality of the fuel introduced into the cylinder during a fuel event may also vary because of the amount of composites such as light hydrocarbons that may be present in the fuel.
Other factors that may change during the combustion event include the amount and quality of air supplied during the combustion event, and the quality of the spark provided by the engine that uses sparks to ignite the fuel. The airflow to the cylinder depends on a variety of factors, including atmospheric pressure and the composition of air, which is a mixture of oxygen used for combustion and many other compounds that often contain impurities that can be introduced into the air stream. It can change.

  Furthermore, liquid fuel such as gasoline burns in a vaporized state. Furthermore, heat is generally a major factor in vaporizing fuel. Such heat can come from a variety of ways, including from contact with hot air, from contact with metal in the immediate vicinity of the warm engine, from contact with the warm valve, piston, or cylinder wall, or from compression in the cylinder. Can be applied at. Accordingly, heat and fuel vaporization caused by partial heat can vary considerably from combustion event to combustion event. It will be appreciated that when the engine is first cold started, the engine and cylinders are not heated, and evaporation may be reduced resulting in another unique engine start situation.

  Engine friction at engine startup is generally higher than under normal operating conditions after startup. Thus, in order to overcome greater frictional forces, the amount of fuel required at start-up is greater than the amount of fuel required during normal operation. Generally, there is a higher friction force in the engine at start-up. This is because the viscosity of the lubricating oil is higher.

  For at least these reasons, a fuel supply that is tuned for normal steady state engine operation may not be suitable for conditions that exist at engine start. Thus, this engine starting device and method may improve engine starting compared to previous systems.

  FIG. 1 illustrates one embodiment of a cylinder of an engine 350 powered by four stroke gasoline that can be used with the present invention. It is understood that other cylinder configurations can be used with the present invention, including, for example, a two-stroke engine, a carburetor engine, a diesel engine, and a fuel injector 312 supplying fuel to one or more cylinders 362. Let's be done. 1 includes a fuel injector 312, an intake pipe 352, an intake valve 354, a spark plug 356, an exhaust valve 358, an exhaust pipe 360, a cylinder 362, and a connecting rod 366 and a crankshaft (not shown) through a bearing 368. ) Connected to the piston 364.

  When a valve (not shown) is opened to allow fuel to flow through the fuel injector 312, the pressurized fuel from a fuel pipe (not shown) coupled to the fuel injector 312 is It can be sprayed through the nozzle 370 of the fuel injector 312. The valve may be an electrically operated solenoid valve that is operated via the output of the engine control unit. Such solenoid valve control is typically performed by pulse width modulation, with longer open periods supplying more fuel to cylinder 362 supplied by fuel injector 312.

  A butterfly valve (not shown) may be arranged to allow airflow to the intake pipe 352 of one or more cylinders 362. The butterfly valve may pivot about an axis between a first position that prevents airflow to the intake pipe 352 and a second position that allows airflow to the intake pipe 352. An actuator cam (not shown) is connected to the butterfly valve so that the butterfly valve is pivoted from the first position to the second position with respect to a bias of an extension spring such as a torsion spring. Also good. The cam of the actuator may be connected to a throttle control element (not shown) controlled by an operator via a throttle cable (not shown). Alternatively, the actuator cam can be controlled by the output of the engine control unit and the operator controlled throttle control element can serve only as an input to the engine control unit.

  The throttle position sensor is connected to the butterfly valve, for example to measure the angular position of the butterfly valve as it pivots about an axis and / or connected to a throttle control element for input to the engine control unit Also good. Further, the amount of fuel may be supplied to one or more cylinders according to a desired ratio of fuel to air, such as a theoretical mixture of 14.7 parts air per part gasoline.

  In a cylinder of a four-stroke engine 350, such as that shown in FIG. 1, fuel can generally flow through intake valve 354 to cylinder 362 or multiple cylinders. The intake valve 354 is then closed and the fuel is ignited by the spark plug 356 thereby driving the piston 364 away from the intake valve 354 and the blow-off valve 358. The exhaust valve 358 opens when the piston 364 returns in the direction of the intake valve 354 and the exhaust valve 358, whereby exhaust gas is ejected from the cylinder 362, passes through the exhaust valve 358, and exits through the exhaust pipe 360.

  Note that the fuel sent to the cylinder 362 often passes through the intake pipe 352 where the fuel can be mixed with an oxidant such as air and drawn into the intake pipe 352. Accordingly, liquid fuel may adhere to the wall 372 of the intake pipe 352 or the back surface of the intake valve 354 on the opposite side of the cylinder. For about a quarter cycle of the cylinder 362 of the four-stroke engine 350 when the intake valve 354 is in the open position, and when the intake valve 354 is in the closed position, such as when the engine is under heavy load, Fuel can be supplied for most of the third quarter. Thus, particularly under such high-load engine conditions, significant fuel deposition can occur in the air stream in the intake pipe wall 372, intake valve 352, and intake pipe 352.

  Engines have common features that may not be universal. One common engine configuration includes several cylinders and is started by an electric motor that rotates the engine while fuel, air, and possibly sparks are supplied to the cylinders. Such electric motors often cause the engine to rotate slowly but continuously. Some cylinders, when ignited, can run the engine without the need for an electric motor and help the electric motor rotate the engine until it is time to stop the operation.

  Another common engine configuration includes one or a few cylinders and is started manually. For example, lawn mowers, chain saws, and other devices can be started using a pull-start mechanism. Furthermore, motorcycle engines have one or two cylinders and can be started by a kickstart device. In general, a kickstart causes the engine to rotate faster than an electric motor when operated powerfully, but if the engine does not start after a limited interval or number of cycles, the engine starts. Try again and kickstart operation is performed again. Of course, there are other starters and methods, and various starters and methods can be adapted to engines of various configurations and sizes having any number of cylinders. However, these two common configurations are used throughout the following description to illustrate engine starting.

  Starting the engine can be difficult, especially for engines with only one, two or three cylinders. In an engine with more cylinders, each cylinder, when ignited or started, helps the engine to rotate, thereby helping to start additional cylinders, which additional cylinders ignite all cylinders To help start more cylinders. For example, in an engine with one cylinder, the first or second cycle (each of which is 360 degrees for a two-stroke engine, because there is no other cylinder that helps the engine to rotate and that one cylinder to ignite) It can be important to start the ignition of the cylinder at 720 degrees for a four-stroke engine). Also, if kickstart is used and the kickstart rotates the engine by one or two cycles, it may be important to start that single cylinder in that first or second cycle.

  In many engine applications, the amount of fuel directed to the engine is determined by a fuel supply map or table. Table 1 shows a simplified version of a general map, but shows the use of the map. Each set point of the map shown in Table 1 corresponds to two values of engine operating characteristics, namely engine speed value and engine load value. Thus, the engine speed (such as sensed by or derived from an output signal from an angular motion sensor of a crankshaft coupled to the engine) and the value of the engine load (measured by a throttle position sensor) Etc.) is assigned a fuel amount set point and can be read from the map. The engine load can also be determined by another sensor, such as a manifold pressure sensor or a mass air flow sensor, and the engine load can be calculated from measurements of one or more sensors.

  For example, the map shown in Table 1 causes the engine control unit to deliver 25 milligrams of fuel per cycle at 2000 revolutions per minute (rpm) when the throttle is 50% open. At 5000 rpm, when the throttle is fully open, the engine control unit changes the fuel delivery to deliver 50 milligrams of fuel per cycle. Thus, when the engine load (such as throttle position) or engine speed changes, the fuel delivery system determines the initial steady state amount of fuel, which is delivered at the new speed and load by referring to the map. The

  In general, the map contains a larger number of set points than those shown in the map shown in Table 1, and therefore, for each engine operating characteristic used in the map, the measurement increment is smaller. You can also assign a set point. In one embodiment, the map includes 17 segments for each of engine speed and engine load. Note that the segments may be equal in increments, or may be divided by unequal increments, and may be either the most beneficial to engine operation.

  If the engine operating state is included in the gap between the specified values of the characteristics (for example, in Table 1, there is a gap of 1000 rpm or more between the specified values for engine speed, and the engine load is 20% or more The engine control unit can interpolate the operational control values between the two nearest speed columns and the two nearest load rows, or the equivalent.

  The map used during normal engine operation is generally optimized for steady state engine operation and is therefore referred to herein as a steady state fuel map. In addition, these maps are generally not optimized for engine start-up and, when referenced, do not provide an adequate amount of fuel for engine start-up. Thus, the fuel supplied when the engine is started may be determined separately from the steady state fuel map, or may include a variation in the amount of fuel supplied based on the steady state fuel map. (E.g., 10% of the fuel supplied during normal operation may be provided when the engine is started).

  One embodiment where the starting fuel supplied to the engine at engine startup is based on fueling a steady state fuel map, the steady state fuel map including 17 segments for engine speed and 17 segments for load. In the second to fifth load categories can be taken into account during engine start-up. It should be understood that other categories can be referenced to suit a particular application. In general, the engine speed is not taken into account in this embodiment, since it is known that the engine is not rotating immediately before starting the engine and is therefore operating at 0 rpm. Therefore, only the first column of steady state fuel map data is used. The sensed temperature or temperatures may be used to determine the amount of starting fuel delivered. For example, engine coolant temperature, exhaust temperature, or another temperature indicative of engine temperature can be used for a function applied to the amount of steady state fuel that is retrieved from the steady state fuel map. Such an engine temperature indicator can be used to increase the amount of fuel delivered at start-up when the engine is cold versus when the engine is warm. Alternatively or additionally, ambient temperature may be considered because the density of air depends at least in part on the temperature of the air. Thus, as the ambient temperature warms, it indicates that the density of air is lower, and the amount of fuel at start-up can be increased. Such a strategy based on a steady state fuel map may be beneficial. This is because this strategy can be portable so that it can be applied to various engines with little or no change.

  The throttle position may be taken into account to indicate the desired load and to match the fuel supplied to the engine to the airflow supplied to the engine. Further, since the second through fifth load categories of the 17 segment map are known to include an amount of fuel suitable for engine startup, the range may be considered during engine startup.

  Thus, in one embodiment in which a function based on engine temperature of steady state fuel quantity is used to calculate the amount of fuel at engine start, the steady state fuel quantity is retrieved from the steady state fuel map. Can do. The amount of steady state fuel may be adjusted based on the current engine temperature to determine the amount of first fuel delivered to the engine. Other functions based on other sensed or stored data may also be applied to this adjusted steady state fuel amount to reach the first fuel amount delivered to the engine.

  For the amount of second fuel delivered to the engine, the same or different multipliers or functions may be applied to the amount of fuel retrieved from the steady state fuel map for the amount of first fuel delivered to the engine. Alternatively, a new amount of fuel may be extracted from the steady state fuel map and a multiplier or other factor applied to the new amount of fuel to reach a second amount of fuel delivered to the engine. The amount of the second fuel is often less than the amount of the first fuel.

  Accordingly, in one embodiment, the amount of fuel retrieved from the steady state fuel map for the first fuel amount is multiplied by a factor of 0.75 and sent to the engine after delivery of the first fuel amount. A second fuel amount is determined.

  In addition, the steady state fuel volume retrieved from the steady state fuel map is used until the engine is started and ready to go into operation according to the steady state fuel map without using start factors or other functions. By applying a multiplier or other function, the amount of additional fuel may be determined.

  It is also possible to provide a primer quantity of fuel before starting the engine. For example, the primer fuel amount may be predetermined or selected based on a steady state fuel map. Further, the amount of primer fuel may be varied based on various parameters, including throttle position, ambient temperature, engine temperature, other engine or engine control parameters that affect engine start-up.

  Instead of or in addition to throttle position, an idle air control valve (IACV) or throttle bypass circuit may be used. The IACV position is generally determined by the engine controller or engine control unit using, for example, current engine temperature and air temperature. In one embodiment, the sum of the throttle position and the equivalent throttle opening at the IACV position can be used to determine the engine load for a map search as used in this embodiment. The steady state fuel supply associated with the sum of the throttle position and the equivalent throttle opening of the IACV is then read from the steady state fuel map and, as described above, appropriate to the steady state fuel quantity. A factor may be multiplied or it may be modified by a function to reach an appropriate starting fuel quantity. As described above, the fuel supply amount for starting depends on the engine temperature.

  In other embodiments, one or more priming fuel tables are used for fuel supply during engine startup. Such priming fuel tables are created for engine startup and may not be suitable for steady state engine operation.

  In one such embodiment, first and second priming fuel columns are provided in the priming fuel table. Furthermore, each of the first and second columns is divided into possible engine load ranges expressed in terms of throttle position. In this embodiment, engine speed may not be taken into account because it is generally known that the engine is not rotating just before the engine is started. Further, the throttle position indicates a combination of the throttle position and an equivalent throttle position associated with the opening of the IACV.

  In this embodiment, each of the first and second priming fuel trains is divided into four parts. Each row corresponds to a throttle position, which may or may not be the same value as that in the steady state fuel supply table. Furthermore, the values may be interpolated in the same way as was done for the steady state fuel supply table.

  Note that instead of throttle position, or a combination of throttle position and IACV, as needed, the IACV position may be used to specify the load to determine fuel flow during startup. For example, the IACV has a range of 0-100%, which may be associated with a priming fuel table section. Alternatively, if an IACV position is used to indicate the starting load, the IACV position may be associated with the corresponding throttle position, for example, so that the full range of IACV corresponds to 0-15% of the throttle range. Good. If it is desirable to consider both the throttle position and the IACV position, relate the IACV position to the throttle position, for example, use the sum of the throttle position and the IACV position to use which value from the priming fuel table to start the engine It may be beneficial to determine what section of the steady state fuel map should be used, or if a steady state fuel map function is used to start the engine . In this way, the engine controller can set the IACV to the desired position and adapt the air and fuel delivered to the engine during start up to engine requirements.

  It may be desirable and possible to make a rapid transition from starting fueling to steady state map fueling using the starting strategy disclosed herein. For example, at least in part, the cylinder generally warms up quickly, thereby helping to vaporize the fuel, so it can transition to steady state map fueling after only one, two, or even a few engine cycles. It is. After one, two, or even a few engine cycles, for example, minimizing the fuel supplied to the engine, facilitating efficient use of the fuel and minimizing unwanted emissions It may be desirable to help create a quick start, especially if kickstart is used.

  Note that the map from which engine fuel supply is taken and engine fuel supply control transitions may be different from the steady state map. Any map can be used for these purposes, including maps specifically configured to deliver fuel at engine start-up, or other maps used for fuel control, and steady state maps can be used for engine control. As often used, steady state maps are provided herein as example maps.

  The amount of fuel directed to the engine may vary depending on, for example, the size and configuration of the engine, but in one embodiment, when the throttle is at the 7% position, the first plumbing fuel train causes 60 mg of fuel to enter the engine. When the throttle is in the 9% position, the first plumbing fuel row is scheduled to send 70 mg of fuel to the engine, and when the throttle is in the 11% position, the first The plumbing fuel train is scheduled to deliver 80 mg of fuel to the engine, and when the throttle is at the 15% position, the first plumbing fuel train is scheduled to deliver 90 mg of fuel to the engine. Further, in that embodiment, when the throttle is at the 7% position, the second plumbing fuel train is scheduled to deliver 40 mg of fuel to the engine, and when the throttle is at the 9% position, the second The plumbing fuel train is scheduled to send 50 mg of fuel to the engine, and when the throttle is at the 11% position, the second plumbing fuel train is scheduled to send 60 mg of fuel to the engine and the throttle is 15 When in the% position, the second plumbing fuel train is scheduled to deliver 70 mg of fuel to the engine. Table 2 shows the configuration of the priming fuel table. It should be understood that the columns can be arranged in other cases as rows, as individual tables, or in other desirable configurations. Engine load values other than the delimiter values can be further interpolated.

  FIG. 2 illustrates a method 100 for starting an engine using a start fuel table by indicating its use using the sample start table of Table 2. At 102, the amount of fuel supplied to the engine during the first cycle of the engine is retrieved from the startup fuel table. The value is found in the first column of the starting fuel table in Table 2 and may be based on the current throttle position. That amount of fuel may be indicated as the mass of the fuel, for example in units of milligrams. At 104, a primer portion of the amount of fuel removed from the first column of the starting fuel table is supplied to the engine prior to the first engine cycle. The primer portion can be, for example, 150% of the amount of fuel removed from the first row of the starting fuel table, and 104 can be performed only when the engine is first cold started. In this embodiment, or in embodiments where the starting fuel is based on a steady state fuel map, the primer portion may instead be calculated from the steady state fuel quantity and supplied to the engine prior to the first engine cycle. Please note that.

  The first engine cold start is a period of time when the engine has not been operated or tried to start, followed by a significant amount of time during which a significant amount of fuel previously supplied to the engine has been vaporized. It is. For a typical engine, the time can range from 15 minutes to several hours. In the first cold start, a change in fuel supply at start-up may be made to supply the first primer fuel quantity to the engine. Thus, primer fuel may be supplied at 104 upon initial engine start-up. Further, the primer fuel may be supplied before the engine is circulated. The initial engine cold start includes many throttle operations beyond a predetermined point, such as 90% of the maximum throttle position by the operator to match the priming of the mechanical fuel delivery system. Can be recognized in a way. The engine controller can also automatically perform priming based on, for example, an elapsed time since the engine is operated, or by reading engine temperature versus temperature.

  At 106, a function based on, for example, engine temperature and possibly air temperature is applied to the amount of fuel extracted from the first column of the starting fuel table, and the resulting amount of fuel is provided to the engine. obtain. This amount of fuel can be supplied during the engine cycle after the primer fuel supply at 104 if the start is the first cold start. Since the primer fuel can be supplied before the engine is circulated, the amount of the first fuel that is removed from the start-up table and adjusted to the engine temperature is supplied to the engine during the first cycle of the engine. Good. If the start is not the first engine start, no priming fuel is supplied to the engine, but nevertheless, it was removed from the first row of the start fuel table at 106 during the first cycle of the engine. A regulated amount of fuel may be supplied to the engine.

  A start that is not the first cold start may include any engine start that occurs immediately after the previously failed start, with fuel remaining in the engine or intake pipe. A start that is not the first cold start may also include any start following normal engine operation and engine shutoff. This is because normal operation can raise the engine temperature or supply the fuel that remains in the engine so that the engine can be restarted, for example, without supplying primer fuel at 104. In these situations, it may be desirable not to supply priming fuel or to reduce the amount of priming fuel to avoid overflowing the engine or to reduce engine emissions. Therefore, the reduced amount of priming fuel may be calculated from, for example, an attenuation coefficient or calculated from a coefficient extracted from the table. Further, the reduced priming amount may be limited to a minimum steady state fuel table value.

  At 108, the amount of fuel delivered to the engine is retrieved from the second column of the priming fuel table, also based on the current throttle position, IACV position, other criteria, or combinations thereof. The amount of fuel withdrawn from the second column of the priming fuel table may then have a function applied to it based on, for example, engine temperature, and possibly air temperature, and is provided to the engine. The amount of fuel is provided during a subsequent engine cycle following the engine cycle in which the amount of fuel drawn from the first column of the priming fuel table is supplied to the engine at 106 or during the second engine revolution. Can be supplied.

  If the engine is started, at 110, fuel supply control may be returned to the steady state fuel map. This rapid transition to a steady state fuel map beneficially minimizes the number of engine cycles where a rich fuel mixture is delivered to the engine, thereby generally improving engine fuel efficiency and abundant, such as during start-up. Minimize unwanted pollutant emissions from common engines when the fuel mixture is burned.

  It should be understood that any desired number of priming fuel tables may be used, and such a priming fuel table may have any number of portions that are divided into any desired stage. It should also be understood that the priming fuel table section may be based on other than throttle position and IACV position. For example, the priming fuel table category may be based on engine temperature.

  In order to optimize engine start-up, the timing of fuel delivery to the engine may be controlled. When the piston in the cylinder is close to its upper center (tdc) position, or when the intake valve is closing, it may be desirable to deliver fuel to the engine cylinder. In one embodiment, it is desirable for fuel to be delivered to each cylinder of the engine in five stages before these cylinders reach the top center.

  The engine position before start-up may be known from previous engine cycling, and when the associated piston reaches the desired position, the engine piston movement can be varied in various known ways so that fuel can be delivered to each cylinder. Can be measured by the method. Alternatively, the engine position prior to starting is not known, but may be sensed when the engine begins to rotate at startup. For example, engine position sensors, such as flywheels, crankshaft position sensors, camshaft position sensors, alternator rotors, and other disks that rotate during engine operation, can be a mark or shape changer such as one or more teeth. These can be used to determine the engine position by sensing the passage of these marks and shapes by the sensor as the disc rotates past the engine position sensor.

  In one embodiment in which a four-stroke engine is started during initial startup, an initial primer fuel amount, such as that described at 104, may be supplied to the engine cylinders prior to initiating engine rotation. The amount of fuel removed from the first column of the priming fuel table can then be supplied to the cylinders of the engine near the upper or lower center during the first 360 degree rotation. Thereafter, the amount of fuel removed from the second column of the priming fuel table can be supplied to the cylinders of the engine near the upper center or near the lower center during the second 360 degree rotation. The fuel control is then returned to the steady state fuel map and fuel can be delivered near the upper center every 720 degrees of rotation.

  In another embodiment where a two-stroke engine is started, the startup procedure is associated with a four-stroke engine, except that normal engine operation provides fuel every 360 degrees instead of every 720 degrees. As described above.

  In one embodiment of engine startup, the amount of fuel supplied to the engine varies with temperature. These temperatures can be one or several temperatures related to engine conditions or ambient conditions. For example, the amount of fuel may vary based on the engine coolant temperature. Further, the amount of fuel delivered can be taken from the appropriate row of the primer fuel table, for example, when the engine coolant is 60 degrees Fahrenheit, and every degree below 60 degrees Fahrenheit. Can be increased by a factor such as 0.02. Alternatively, the amount of fuel added to the amount read from the appropriate primer fuel table may be retrieved from the temperature table.

  In another embodiment of starting the engine, the product, when executed by the processor, causes the processor to perform the method described in connection with FIG. 2 and variations described elsewhere herein. A computer readable medium storing instructions is included.

  FIG. 3 illustrates one embodiment of an engine control system 150 that may be used to start the engine. Engine control system 150 includes an internal combustion engine 172 having a cylinder 174 and a crankshaft 176. The cylinder 174 includes a piston 178 having a connecting rod 180 that connects to the crankshaft 176. The intake valve 182, the exhaust valve 184, and the spark plug 186 extend into the cylinder 174.

  The intake control device 188 and the fuel supply control device 204 supply air and fuel to the intake valve 182 and the cylinder 174. Intake control unit 188 may include, for example, a butterfly valve 192 or a gate valve for controlling the amount of combustion air sent to engine 172. The air mass sensor 194 can be, for example, a temperature or pressure sensor and is used to measure the airflow to the engine and can be located in the intake control. The air temperature sensor 168 may be used to measure the intake air temperature and send a signal 170 to the engine control unit 154.

  The fuel supply control device 204 can be, for example, a fuel injector 206 or a carburetor. An actuator for controlling the fuel flow rate may be coupled to the fuel injector 206 or the carburetor via the fuel injector 206 or the carburetor. A signal, such as a pulse width modulated signal, may be transmitted from the engine control unit 154 to the actuator to provide fuel flow through the fuel injector 206 or carburetor.

  The throttle position sensor 196 may be connected to sense the position of the throttle switch 198 that is activated by the operator as an indicator of the desired engine load. Engine encoder 200 can sense rotation of crankshaft 176 as an indicator of actual engine speed. The battery 202 can supply power to the portion of the engine control system 150 that requires power.

The cooling water temperature sensor 210 may be provided for sensing the temperature of the engine cooling water 212 that flows to the engine 150 through the cooling water chamber 214.
While the components of the engine control system 150 operate in a known manner, the control of the amount of fuel supplied, for example, by the fuel supply device 204, includes the start fuel table and start fuel supply, as shown in FIG. May be modified to start the engine 100 using a steady state fuel map by the engine control unit 154 using the method described in the above. For example, in the engine control system 150 of FIG. 3, one embodiment of engine startup may be performed by the processor 152 of the engine control unit 154. In that embodiment, one or more input signals 156, 158, 170, and 216 are received at the input board 160 of the engine control unit 154.

  The processor 152 may be coupled to the memory 162 and may execute program instructions and process information stored in the memory 162. Information can include any data that can be represented as a signal, such as an electrical signal, an optical signal, an acoustic signal, and the like. Examples of information in this context may include quantities supplied to the engine 172, such as steady state fuel maps, startup fuel tables, and the like.

  In one embodiment, the instructions are stored in memory 162 in machine readable form. As used herein, the phrase “executed by a processor” is intended to include instructions stored in a machine-readable form and instructions that can be compiled or installed by an installer before being executed by the processor 152.

  The memory 162 may be, for example, random access memory (RAM) such as cache, dynamic RAM and static RAM, read only memory (ROM) such as programmable ROM, erasable PROM, or electrically erasable PROM, or a magnetic disk And high capacity devices such as optical disks. Memory 162 may store computer program instructions and information. Memory 162 is further divided into sections containing an operating system partition that stores instructions including those that perform engine startup, and a data partition that can store information such as values retrieved from steady state maps and startup tables. May be.

  Signals 156, 158, 170, and 216 in that embodiment are respectively from throttle position sensor 196, engine speed sensor 200, temperature sensor 168, and cooling water temperature sensor 210 in engine control system 150 shown in FIG. Received. Input board 160 receives and samples signals 156, 158, 170, and 216, generates each signal 156, 158, and 216, and provides processor 152 with a value that corresponds to the sensed value. Note that other signals from sensors such as barometric sensors may also be sampled and used. The processor 152 then generates each signal 156, 158, 170, and 216 and provides a value corresponding to the sensed value to the processor as a ratio of position at the throttle position sensor 196, rotation at the engine speed sensor 200. Instructions can be executed to convert to a value having engineering units appropriate to the sensed medium, such as a number or rpm, and degrees at cooling water temperature sensor 210 and temperature sensor 168. The processor 152 can then execute instructions that cause the processor to calculate the amount of fuel delivered to the engine, as described herein. The processor 152 may further provide one or more via an output board 164, such as an output 166, to a fuel supply device, such as the illustrated fuel injector 206 or carburetor, based on the results of the determination of the fuel amount of the engine. Output can be provided.

  In one embodiment of the engine start shown in FIG. 4, engine fuel supply 250 is used to start engine 172. Engine fuel supply 250 includes a processor 252 for receiving a signal 256 corresponding to the desired engine load and outputting a signal 266 corresponding to the amount of fuel supplied to engine 172. The processor 252 may also receive other signals including the current engine load signal (not shown) and output additional signals to provide full or partial engine control. The processor 252 can determine the amount of fuel supplied to start the engine 172, which corresponds to the value generated in the signal 256 corresponding to the desired engine load. The amount of fuel may be determined by referring to the starting fuel table 262 at a location corresponding to the desired engine load, as described herein. Alternatively, the amount of fuel is supplied to start the engine 172 by referring to a fuel supply map, such as a steady state fuel supply map 258, at a location corresponding to the desired engine load, as described herein. May be determined by applying a function to the amount of fuel retrieved from the fuel supply map so as to reach the amount of fuel to be achieved.

  The desired engine load may be sensed by throttle position sensor 298, IACV, throttle throttle circuit, or the like. A signal 266 corresponding to the amount of fuel supplied to the engine 172 may also be transmitted to a fuel supply control device 204 such as the fuel injector 206. After the engine 172 is started, the fuel supply controller 204 can provide a fuel supply signal 266 that corresponds to the sensed current engine speed and the amount of fuel supplied at the desired load. A transition may be made to control based on a fuel supply map such as map 258.

  It should be understood that the engine configuration shown herein, and the amount of fuel described herein has been used to illustrate and explain problems associated with starting the engine. It should also be understood that engine starting may be applied to other engines having other configurations and using other amounts of fuel.

It is a cross-sectional view showing an embodiment of a cylinder in a 4-stroke engine. FIG. 2 shows an embodiment of a method for starting an engine. 1 is a diagram showing an embodiment of an engine control system capable of starting an engine. It is a figure which shows one Embodiment of the engine fuel supply apparatus with which the fuel containing start-up combustion may be supplied to an engine.

Claims (31)

An engine starting method,
Determining an amount of the first fuel based on the temperature of the engine;
Supplying an amount of the first fuel to the engine during a first cycle of the engine;
Determining an amount of a second fuel based on the temperature of the engine;
Then supplying the second amount of fuel to the engine;
Transitioning to an alternative fuel supply strategy.   The engine start method of claim 1, wherein engine speed is not considered in determining the first and second fuel quantities, and engine speed is considered in an alternative fuel delivery strategy.   The engine start method of claim 1, wherein an amount of a third fuel is determined based on engine temperature, and the amount of the third fuel is supplied to the engine before transitioning to the alternative fuel supply strategy. .   The engine start method of claim 1, wherein the amounts of the first and second fuels are further determined based on a temperature of air entering the engine.   The engine start method according to claim 1, wherein the amounts of the first and second fuels are further determined based on a pressure of air entering the engine.   The engine starting method according to claim 1, wherein the amounts of the first and second fuels are further determined based on an engine load.   The engine start method according to claim 1, wherein the amounts of the first and second fuels are further determined based on a throttle position.   The engine start method according to claim 1, wherein the amounts of the first and second fuels are further determined based on an idle air control valve position.   The engine starting method according to claim 1, wherein the amounts of the first and second fuels are further determined based on a throttle bypass circuit.   The engine start method of claim 1, further comprising providing a priming fuel amount prior to the first cycle of the engine.   The engine starting method according to claim 10, wherein the priming fuel amount is supplied when a throttle is actuated past a predetermined point.   The engine starting method according to claim 1, wherein the engine is started by a mechanism operated manually.   The engine starting method according to claim 1, wherein the engine is started by a battery operated mechanism.   The engine start method according to claim 1, wherein the amount of the second fuel is determined based on the amount of the first fuel. The engine is a four-stroke engine;
The amount of the first fuel is delivered during a first 360 degree engine rotation;
The engine start method according to claim 1, wherein the amount of the second fuel is delivered during a second 360-degree engine rotation. An engine starting method,
Taking the amount of the first fuel from the starting fuel table based on the engine temperature;
Supplying an amount of the first fuel to the engine during a first cycle of the engine;
Retrieving a second fuel quantity from the starting fuel table based on engine temperature;
Then supplying the second amount of fuel to the engine;
Transitioning to an alternative fuel supply strategy.   The engine start method of claim 16, wherein engine speed is not considered in determining the first and second fuel quantities, and engine speed is considered in an alternative fuel delivery strategy.   17. A third fuel quantity is retrieved from the startup fuel table based on engine temperature and the third fuel quantity is supplied to the engine before transitioning to the alternative fuel delivery strategy. The engine starting method as described in 2.   The engine start method of claim 16, wherein the amounts of the first and second fuels are further based on the temperature of the air entering the engine.   The engine start method of claim 16, wherein the amounts of the first and second fuels are further based on air pressure entering the engine.   The engine start method according to claim 16, wherein the amounts of the first and second fuels are further based on an engine load.   The engine start method of claim 16, wherein the amounts of the first and second fuels are further based on a throttle position.   The engine start method of claim 16, wherein the first and second fuel amounts are further based on an idle air control valve position.   The engine start method of claim 16, wherein the amounts of the first and second fuels are further based on a throttle bypass circuit.   The engine start method of claim 16, further comprising providing a priming fuel amount prior to the first cycle of the engine.   The engine starting method according to claim 16, wherein the engine is started by a mechanism operated manually.   The engine starting method according to claim 16, wherein the engine is started by a battery operated mechanism. An engine starting method,
Taking the amount of the first fuel from the starting fuel table based on the engine temperature;
Supplying an amount of the first fuel to the engine during a first cycle of the engine;
Determining a second fuel amount from the first fuel amount;
Then supplying the second amount of fuel to the engine;
Transitioning to an alternative fuel supply strategy. Coupled to the signal corresponding to the engine temperature,
A processor coupled to the fuel supply control device;
The processor is
Determining the amount of the first fuel based on the temperature of the engine;
Supplying an amount of the first fuel to the engine via the fuel supply controller during a first cycle of the engine;
Determine the amount of the second fuel based on the temperature of the engine;
After supplying the amount of the first fuel, supplying the amount of the second fuel to the engine via the fuel supply control device;
Engine fuel supply equipment to shift to alternative fuel supply strategies.   The engine fuel supply device according to claim 34, wherein the fuel supply control device is a fuel injector. A computer readable medium storing instructions, when executed by a processor,
Let the amount of the first fuel be determined based on the temperature of the engine;
Causing the engine to supply an amount of the first fuel via the fuel supply control device during a first cycle of the engine;
Let the amount of the second fuel be determined based on the temperature of the engine,
After supplying the amount of the first fuel, the amount of the second fuel is supplied to the engine via the fuel supply control device,
A computer readable medium for transitioning to alternative fuel supply strategies.

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